The present invention relates to image pickup apparatus, and more particularly relates to an image pickup apparatus in which fault pixels of a semiconductor image pickup device can be interpolated and compensated at high accuracy.
In general, when an image is taken by using an image pickup apparatus having a semiconductor image pickup device which comprises two-dimensionally arrayed pixels, faults occur in image pickup signal and a poor image output results when defect occurs in the pixels of the semiconductor image pickup device. Means of various kinds for compensating pixel defects have been used to make less conspicuous such defects in the output image. Known among the fundamental compensation systems is a system in which signals of the pixels around a fault pixel are used to replace the signal of the fault pixel (4-point interpolation system).
Further, Japanese Patent Publication No. 5-23551 discloses an image defect compensation apparatus in which fault pixel signals can be compensated more accurately by reducing compensation error. It includes: an absolute value operation means for outputting absolute value signals by computing from pixel signals outputted from a plurality of image pickup devices arranged in a square matrix, absolute values of difference between respective two pixels between which a fault pixel signal is sandwiched in vertical, horizontal and slanting directions; a minimum difference detection means for detecting two pixel signals from which the smallest of the absolute value signals is derived; an average value operation means for computing an average value of the two pixel signals detected by the minimum difference detection means and outputting an average value signal; and a replacing means for replacing the fault pixel signal by the average value signal.
Here, supposing as shown in FIG. 1A a pixel 101 at the location indicated by a blank in the two pixel rows for outputting a black line in the horizontal direction as a fault pixel, a defect compensation system based on the 4-point compensation of surrounding pixels as described above is the system in which the fault pixel is replaced by an average value of those pixels indicated by the arrows, located above, below, and on the left and right sides of the fault pixel 101. When the fault pixel 101 shown in FIG. 1A is interpolated by this system, the interpolation using the average value results in an interpolation by a gray level as shown in FIG. 1B, since three pixels out of those used for interpolation are black and the other one is white. Thus, the fault pixel shown in FIG. 1A, while it should be interpolated by black, is interpolated by gray and some of the defect is uncorrected. If, therefore, the defect is in a region (for example a line or edge) where a steep change in luminance occurs within the image, a problem is caused that the interpolation error becomes greater and an effective compensation of the fault pixel is impossible. Further, according to the above described image defect compensation apparatus disclosed in Japanese Patent Publication No. 5-23551, though the compensation error becomes smaller and it is possible to compensate the fault pixel at high accuracy, only the two pixels by which the fault pixel is sandwiched in the vertical, horizontal or slanting directions are considered and hence the manner of pixel signals in a region surrounding the fault pixel cannot be accurately considered. This also results in a problem that a compensation of the fault pixel at high accuracy may not be possible in a region where luminance is steeply changing.
To eliminate the above problems in the fault pixel compensation systems used in conventional image pickup apparatus, it is a main object of the present invention to provide an image pickup apparatus in which fault pixels can be compensated at high accuracy so as to make defect less conspicuous even when the defect is in a region where luminance steeply changes within an output image, by considering an image configuration in the region surrounding the fault pixels.
In a first aspect of the present invention, there is provided an image pickup apparatus including: an image pickup means having a semiconductor image pickup device composed of two-dimensionally arrayed pixels, for converting object light into image signals; a fault pixel detection means for obtaining the position of fault pixels in the semiconductor image pickup device and, if the fault pixels are two-dimensionally consecutive, additionally obtaining a pattern of order of the fault pixels; a fault pixel information storage means for storing information concerning the fault pixels obtained at the fault pixel detection means; a surrounding image configuration detection means for detecting from information of pixels surrounding the fault pixels an image configuration of a region surrounding a fault pixel location obtained by the fault pixel detection means in the image signals obtained from the image pickup means; and a pixel defect compensation means for selecting pixels from a surrounding of the fault pixels based on the image configuration detected by the surrounding image configuration detection means and performing pixel defect compensation by interpolating the fault pixels using the selected pixels.
Since the image configuration (line and its direction, edge and its direction, surface) of a region surrounding the fault pixels within an image is thus detected by the surrounding image configuration detection means and the pixels for interpolating the fault pixels are selected based on the image configuration, it is possible to achieve an image pickup apparatus in which compensation at high accuracy is possible so as to make defect less conspicuous even when the defect occurs in a region (for example line or edge) where luminance changes steeply in the output image. The above main object is thereby accomplished.
It is another object of the present invention to provide an image pickup apparatus in which, when fault pixels are two-dimensionally consecutive, processing for defect compensation is possible by a storage means having a relatively small memory capacity.
In a second aspect of the invention, the fault pixel information storage means in the image pickup apparatus according to the above first aspect, when fault pixels are two-dimensionally consecutive, stores the pixel location of one of the consecutive fault pixels and a pattern of order of the other fault pixels. Since the location of one of the fault pixels and order of the other fault pixels are stored as described if the fault pixels are two-dimensionally consecutive, a smaller memory capacity suffices when compared with the case of storing fault pixel location for each one pixel. The above object is thereby accomplished.
It is still another object of the present invention to provide an image pickup apparatus in which fault pixels can be accurately compensated by detecting at high accuracy an image configuration of a region surrounding a fault pixel location.
In a third aspect of the invention, the surrounding image configuration detection means in the image pickup apparatus according to the above first or second aspect includes: a signal level detection means for obtaining respective signal levels of a plurality of pixels surrounding a fault pixel; a first relative level detection means for, of signal level data of the plurality of pixels obtained from the signal level detection means, placing those of a plurality of pixels located above the fault pixel together into a horizontally oriented group, the signal level of one pixel in the group used as a reference pixel signal level to obtain relative signal levels of the other pixels with respect to the reference pixel signal level; a second relative level detection means for, of signal level data of the plurality of pixels obtained from the signal level detection means, placing those of a plurality of pixels located below the fault pixel together into a horizontally oriented group, the signal level of one pixel in the group used as a reference pixel signal level to obtain relative signal levels of the other pixels with respect to the reference pixel signal level; a third relative level detection means for, of signal level data of the plurality of pixels obtained from the signal level detection means, placing those of a plurality of pixels located on the right side of the fault pixel together into a vertically oriented group, the signal level of one pixel in the group used as a reference pixel signal level to obtain relative signal levels of the other pixels with respect to the reference pixel signal level; a fourth relative level detection means for, of signal level data of the plurality of pixels obtained from the signal level detection means, placing those of a plurality of pixels located on the left side of the fault pixel together into a vertically oriented group, the signal level of one pixel in the group used as a reference pixel signal level to obtain relative signal levels of the other pixels with respect to the reference pixel signal level; a pattern means for representing the relative signal level data obtained at the first to fourth relative level detection means in connection with pixel locations to pattern the pixel signal levels within each group; a comparison means for comparing the patterns obtained at the pattern means with previously set patterns; a first image configuration determination means for, in case that the patterns obtained at the pattern means are matched by the set pattern in the comparing operation at the comparison means, determining the matching set pattern as a surrounding image configuration; a second image configuration determination means for, in case that the patterns obtained at the pattern means are matched by none of the set patterns in the comparing operation at the comparison means, determining a previously set specific pattern as a surrounding image configuration; and a third image configuration determination means for, in case that the patterns obtained at the pattern means are matched by plural ones of the previously set patterns in the comparing operation at the comparison means, selecting from the plurality of matching set patterns one pattern having a smallest signal level difference among a plurality of interpolation pixels indicated by such set patterns to determine it as a surrounding image configuration.
In a fourth aspect of the invention, the pattern means in the image pickup apparatus according to the above third aspect makes the pixel signal levels in each group into a pattern by representing the relative signal level data in connection with pixel locations using an N-ary (N being a suitable number equal to or less than the number of gradations of image signal by the image pickup means). In a fifth aspect of the invention, the N-ary in the image pickup apparatus according to the above described fourth aspect is a ternary system where, of the signal levels of the plurality of pixels, each signal level of the other pixels is higher or lower than or the same as the reference pixel signal level. In a sixth aspect of the invention, the previously set patterns used in the comparison means in the image pickup apparatus according to the above fifth aspect are the patterns by which the direction of edges and lines can be determined.
As described, in the image pickup apparatus according to the above third to sixth aspects, the relative signal levels of pixels respectively located in the four directions surrounding a fault pixel from upper and lower and left and right sides thereof are made into patterns in connection with pixel locations, which are compared with previously set patterns to obtain an image configuration of a region surrounding the fault pixel. The image configuration can thus be detected at high accuracy so as to accurately compensate the fault pixel. The above object is thereby accomplished.
It is yet another object of the present invention to provide an image pickup apparatus in which an image configuration of a region surrounding a fault pixel location can be detected at high accuracy without increasing the region and an image configuration of the surrounding region in a slanting form can also be easily detected with including the direction thereof so that fault pixels can be compensated at high accuracy.
In a seventh aspect of the invention, the surrounding image configuration detection means in the image pickup apparatus according to the above first aspect includes: a reference pixel signal level detection means for determining as reference pixels a plurality of pixels surrounding a fault pixel and for obtaining the signal levels of the reference pixels; a first signal level detection means for detecting the signal levels of a first plurality of pixels respectively at locations uniformly shifted in the horizontal direction from the reference pixels without overlapping the fault pixel; a second signal level detection means for detecting the signal levels of a second plurality of pixels respectively at locations uniformly shifted in the vertical direction from the reference pixels without overlapping the fault pixel; a third signal level detection means for detecting the signal levels of a third plurality of pixels respectively at locations uniformly shifted toward the upper right from the reference pixels without overlapping the fault pixel; a fourth signal level detection means for detecting the signal levels of a fourth plurality of pixels respectively at locations uniformly shifted toward the lower right from the reference pixels without overlapping the fault pixel; a means for obtaining for each vertical line sum of signal levels of the pixels of the reference pixels on the same vertical line; a means for obtaining for each vertical line sum of signal levels of the pixels of the first plurality of pixels located on the same vertical line; a means for obtaining for each vertical line sum of signal levels of the pixels of the second plurality of pixels located on the same vertical line; a means for obtaining for each vertical line sum of signal levels of the pixels of the third plurality of pixels located on the same vertical line; a means for obtaining for each vertical line sum of signal levels of the pixels of the fourth plurality of pixels located on the same vertical line; a means for, of the reference pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for, of the first plurality of pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for, of the second plurality of pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for, of the third plurality of pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for, of the fourth plurality of pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for comparing the ratios of the signal level sums of the reference pixels with the ratios of the signal level sums, respectively, of the first, second, third and fourth to select the ratios of the signal level sums closest in value to the ratios of the signal level sums of the reference pixels; and a means for determining an image configuration of the surrounding region as a horizontally oriented edge or line when the ratios of the signal level sums of the first plurality of pixels are selected by the means for selecting, determining an image configuration of the surrounding region as a vertically oriented edge or line when the ratios of the signal level sums of the second plurality of pixels are selected, determining an image configuration of the surrounding region as a rightwardly ascending edge or line when the ratios of the signal level sums of the third plurality of pixels are selected, or determining an image configuration of the surrounding region as a rightwardly descending edge or line when the ratios of the signal level sums of the fourth plurality of pixels are selected.
In this manner, pixels surrounding a fault pixel and pixels at locations shifted horizontally, vertically, upper rightward and lower rightward from the surrounding pixels are used to detect an image configuration of a region surrounding the fault pixel. It is thereby possible to detect an image configuration of the surrounding region at high accuracy without an increase in the region for detecting the image configuration. Further, an image configuration of the surrounding region in slanting directions can also be readily detected with including the direction thereof. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus in which detection of image configuration can be efficiently performed irrespective of the presence of a slanting image form in a region surrounding the fault pixel location.
In an eighth aspect of the invention, the surrounding image configuration detection means in the image pickup apparatus according to the above first aspect includes: a first surrounding image configuration detection means composed of the surrounding image configuration detection means according to the above third aspect; and a second surrounding image configuration detection means composed of the surrounding image configuration detection means according to the above seventh aspect. Detection of surrounding image configuration by the second surrounding image configuration detection means is performed only when a slanting line form is detected by the first surrounding image configuration detection means. By this construction, a detection of image configuration can be efficiently performed irrespective of the presence of image form along a slanting direction in the surrounding region of the fault pixel location. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus in which, even when the direction is erroneously detected of an image configuration of the surrounding region of a fault pixel location, the fault pixel can be compensated without making it conspicuous.
In a ninth aspect of the present invention, the pixel defect compensation means in the image pickup apparatus according to the above first to eighth aspect interpolates a fault pixel by an average value of a plurality of selected pixels. By this construction, since the change is smooth between the fault pixel and surrounding pixels even if the direction is erroneously detected of an image configuration of the surrounding region of a fault pixel location, the fault pixel can be compensated without making it conspicuous. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus in which a defect can be compensated without making it conspicuous even when the defect is in a region where luminance steeply changes within a color output image.
In a tenth aspect of the invention, there is provided an image pickup apparatus including: an image pickup means having a semiconductor image pickup device composed of two-dimensionally arrayed pixels, for converting object light into image pickup signals consisting of at least three kinds of color signals; a fault pixel detection means for obtaining the position of fault pixels in the semiconductor image pickup device and, if the fault pixels are two-dimensionally consecutive, additionally obtaining a pattern of order of the fault pixels; a fault pixel information storage means for storing information concerning the fault pixels obtained at the fault pixel detection means; a surrounding image configuration detection means for detecting from information of pixels of the same color as a fault pixel surrounding the fault pixel an image configuration of a region surrounding a fault pixel location obtained by the fault pixel detection means in the image signals obtained from the image pickup means; and a pixel defect compensation means for selecting pixels of the same color as a fault pixel from the surrounding of the fault pixels based on the image configuration detected by the surrounding image configuration detection means and performing pixel defect compensation by interpolating the fault pixels using the selected pixels.
By this construction, it is possible to achieve an image pickup apparatus in which color images can be obtained as compensated so as not to make defect conspicuous even when the defect occurs in a region of color output image where luminance steeply changes. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus in which, when fault pixels are two-dimensionally consecutive in a color image, processing for defect compensation is possible by a storage means having a relatively small memory capacity.
In an eleventh aspect of the invention, the fault pixel information storage means in the image pickup apparatus according to the above tenth aspect, when fault pixels are two-dimensionally consecutive, stores the pixel location of one of the consecutive fault pixels and a pattern of order of the other fault pixels. Since the location of one of the fault pixels and order of the other fault pixels are stored as described if the fault pixels are two-dimensionally consecutive, compensation of fault pixels in a color image is possible at high accuracy by using a smaller memory capacity when compared with the case of storing fault pixel location for each one pixel. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus in which fault pixels can be accurately compensated by detecting at high accuracy the image configuration of the region surrounding the location of a fault pixel in a color image.
In a twelfth aspect of the invention, the surrounding image configuration detection means in the image pickup apparatus according to the above tenth or eleventh aspect includes: a signal level detection means for obtaining respective signal levels of a plurality of pixels of the same color as a fault pixel surrounding the fault pixel; a first relative level detection means for, of signal level data of the plurality of pixels obtained from the signal level detection means, placing those of a plurality of pixels located above the fault pixel together into a horizontally oriented group, the signal level of one pixel in the group used as a reference pixel signal level to obtain relative signal levels of the other pixels with respect to the reference pixel signal level; a second relative level detection means for, of signal level data of the plurality of pixels obtained from the signal level detection means, placing those of a plurality of pixels located below the fault pixel together into a horizontally oriented group, the signal level of one pixel in the group used as a reference pixel signal level to obtain relative signal levels of the other pixels with respect to the reference pixel signal level; a third relative level detection means for, of signal level data of the plurality of pixels obtained from the signal level detection means, placing those of a plurality of pixels located on the right side of the fault pixel together into a vertically oriented group, the signal level of one pixel in the group used as a reference pixel signal level to obtain relative signal levels of the other pixels with respect to the reference pixel signal level; a fourth relative level detection means for, of signal level data of the plurality of pixels obtained from the signal level detection means, placing those of a plurality of pixels located on the left side of the fault pixel together into a vertically oriented group, the signal level of one pixel in the group used as a reference pixel signal level to obtain relative signal levels of the other pixels with respect to the reference pixel signal level; a pattern means for representing the relative signal level data obtained at the first to fourth relative level detection means in connection with pixel locations to pattern the pixel signal levels within each group; a comparison means for comparing the patterns obtained at the pattern means with previously set patterns; a first image configuration determination means for, in case that the patterns obtained at the pattern means are matched by the set pattern in the comparing operation at the comparison means, determining the matching set pattern as a surrounding image configuration; a second image configuration determination means for, in case that the patterns obtained at the pattern means are matched by none of the set patterns in the comparing operation at the comparison means, determining a previously set specific pattern as a surrounding image configuration; and a third image configuration determination means for, in case that the patterns obtained at the pattern means are matched by plural ones of the previously set patterns in the comparing operation at the comparison means, selecting from the plurality of matching set patterns one pattern having a smallest signal level difference among a plurality of interpolation pixels indicated by such set patterns to determine it as a surrounding image configuration.
In a thirteenth aspect of the invention, the pattern means in the image pickup apparatus according to the above twelfth aspect makes the pixel signal levels in each group into a pattern by representing the relative signal level data in connection with pixel locations using an N-ary (N being a suitable number equal to or less than the number of gradations of image signal by the image pickup means). In a fourteenth aspect of the invention, the N-ary in the image pickup apparatus according to the above described thirteenth aspect is a ternary system where, of the signal levels of the plurality of pixels, each signal level of the other pixels is higher or lower than or the same as the reference pixel signal level. In a fifteenth aspect of the invention, the previously set patterns used in the comparison means in the image pickup apparatus according to the above twelfth aspect are the patterns by which the direction of edges and lines can be determined.
As described, in the image pickup apparatus according to the above twelfth to fifteenth aspects, the relative signal levels of pixel groups respectively located in the four directions surrounding a fault pixel from upper and lower and left and right sides thereof are made into patterns in connection with pixel locations, which are compared with previously set patterns to obtain an image configuration of a region surrounding the fault pixel. The image configuration can be detected at high accuracy and it is possible to accurately compensate the fault pixel even in a color image. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus in which image configuration of a region surrounding a fault pixel location can be detected by means of comparison even between pixels of different colors and at the same time an image configuration of the surrounding region of the fault pixel location even in a slanting form is detected at high accuracy with including the direction thereof without increasing the region, thereby making possible a highly accurate compensation of fault pixels.
In a sixteenth aspect of the invention, the surrounding image configuration detection means in the image pickup apparatus according to the above tenth aspect includes: a reference pixel signal level detection means for determining as reference pixels a plurality of pixels of the same color as a fault pixel surrounding the fault pixel and for obtaining the signal levels of the reference pixels; a first signal level detection means for detecting the signal levels of a first plurality of pixels all of the same color respectively at locations uniformly shifted in the horizontal direction from the reference pixels without overlapping the fault pixel; a second signal level detection means for detecting the signal levels of a second plurality of pixels all of the same color respectively at locations uniformly shifted in the vertical direction from the reference pixels without overlapping the fault pixel; a third signal level detection means for detecting the signal levels of a third plurality of pixels all of the same color respectively at locations uniformly shifted toward the upper right from the reference pixels without overlapping the fault pixel; a fourth signal level detection means for detecting the signal levels of a fourth plurality of pixels all of the same color respectively at locations uniformly shifted toward the lower right from the reference pixels without overlapping the fault pixel; a means for obtaining for each vertical line sum of signal levels of the pixels of the reference pixels on the same vertical line; a means for obtaining for each vertical line sum of signal levels of the pixels of the first plurality of pixels located on the same vertical line; a means for obtaining for each vertical line sum of signal levels of the pixels of the second plurality of pixels located on the same vertical line; a means for obtaining for each vertical line sum of signal levels of the pixels of the third plurality of pixels located on the same vertical line; a means for obtaining for each vertical line sum of signal levels of the pixels of the fourth plurality of pixels located on the same vertical line; a means for, of the reference pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for, of the first plurality of pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for, of the second plurality of pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for, of the third plurality of pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for, of the fourth plurality of pixels, obtaining ratios with respect to the signal level sum of the pixels on a predetermined vertical line of the signal level sums of the pixels on all the other vertical lines; a means for comparing the ratios of the signal level sums of the reference pixels with the ratios of the signal level sums, respectively, of the first, second, third and fourth to select the ratios of the signal level sums closest in value to the ratios of the signal level sums of the reference pixels; and a means for determining an image configuration of the surrounding region as a horizontally oriented edge or line when the ratios of the signal level sums of the first plurality of pixels are selected by the means for selecting, determining an image configuration of the surrounding region as a vertically oriented edge or line when the ratios of the signal level sums of the second plurality of pixels are selected, determining an image configuration of the surrounding region as a rightwardly ascending edge or line when the ratios of the signal level sums of the third plurality of pixels are selected, or determining an image configuration of the surrounding region as a rightwardly descending edge or line when the ratios of the signal level sums of the fourth plurality of pixels are selected.
By this construction, since a strong correlation in relative change of luminance (i.e., level ratio) is likely to occur even between pixels of different colors, pixels all of the same color at the locations shifted horizontally, vertically, upper rightward and lower rightward from such pixels are used to detect an image configuration of a region surrounding the fault pixel. An image configuration of a surrounding region of the fault pixel in a color image can thus be detected at high accuracy without an increase in the region for detecting the image configuration and an image configuration of the surrounding region in slanting directions can also be readily detected with including the direction thereof. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus in which detection of image configuration can be efficiently performed in a color image irrespective of the presence of a slanting image form in a region surrounding the fault pixel location.
In a seventeenth aspect of the invention, the surrounding image configuration detection means in the image pickup apparatus according to the above tenth aspect includes: a first surrounding image configuration detection means composed of the surrounding image configuration detection means as disclosed in the above twelfth aspect; and a second surrounding image configuration detection means composed of the surrounding image configuration detection means as disclosed in the above sixteenth aspect. Detection of surrounding image configuration by the second surrounding image configuration detection means is performed only when a slanting line form is detected by the first surrounding image configuration detection means. By this construction, a detection of image configuration can be efficiently performed irrespective of the presence of image form along a slanting direction in the surrounding region of the fault pixel location in a color image. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus in which, even when the direction is erroneously detected of an image configuration of the surrounding region of a fault pixel location, a color image can be obtained as compensated for the fault pixel without making it conspicuous.
In an eighteenth aspect of the invention, the pixel defect compensation means in the image pickup apparatus according to the above tenth to seventeenth aspect interpolates a fault pixel by an average value of a plurality of selected pixels of the same color as the fault pixel. By this construction, since the change is smooth between the fault pixel and surrounding pixels in a color image even if the direction is erroneously detected of an image configuration of the surrounding region of a fault pixel location, the fault pixel in color image can be compensated without making it conspicuous. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus adapted so as not to be affected by the defect when picked up images are compressed to be recorded.
In a nineteenth aspect of the invention, the image pickup apparatus according to the above first to eighteenth aspect further includes a means by which image pickup signal having been compensated for fault pixels at the pixel defect compensation means is compressed and recorded to a recording medium. By this construction, since the image pickup signal is compressed and recorded to the recording medium after compensating for the defect, it is possible to prevent an effect produced by defect when the picked up images are compressed to be recorded. The above object is thereby accomplished.
It is a further object of the present invention to provide an image pickup apparatus capable of reducing time duration for recording of picked up images and of performing compensation of fault pixels at high accuracy.
In a twentieth aspect of the invention, the image pickup apparatus according to the above first to nineteenth aspect further includes: an auxiliary defect compensation means for interpolating a fault pixel of the semiconductor image pickup device by pixels surrounding the fault pixel; a means for compressing and recording to a recording medium image signal having been subjected to fault pixel compensation at the auxiliary defect compensation means; and a means for expanding image signal read out from the recording medium and reproducing it with performing pixel defect compensation by the pixel defect compensation means.
In thus constructed image pickup apparatus, a less accurate defect compensation is performed at the time of recording by the auxiliary defect compensation means of high processing speed and a highly accurate defect compensation is performed at the time of reproduction. It is thereby possible both to reduce the time duration for recording picked up images and to obtain an output image compensated for fault pixels at high accuracy. The above object is thereby accomplished.